1. Field of the Invention
This invention relates to portable turning lathes utilized to machine large shafts and the like and in particular it relates to a portable lathe that can be mounted from the side of the shaft as well as from the end of the shaft for machining a section intermediate the shaft ends.
2. Background of the Invention
There are many types of lathes on the market with the majority having a common factor. A member to be machined is brought to and positioned in a holding apparatus provided on the lathe. The member is rotated by the headstock spindle of the lathe and machining operations are performed.
There are a number of applications where due to the size or nature of the work piece, it is not feasible to transport the work piece and instead it is desirable to have the capability of transporting the lathe to the work piece and to have the machining operations performed without rotating the work piece. This applies to situations such as where a large shaft is assembled to a unit by numerous and cumbersome structure. One example is a wheel supporting spindle on the end of an axle structure of a truck. When a bearing failure damages the spindle, it takes many hours to remove the axle assembly from the vehicle. Additionally, a very large lathe is required to handle the axle assembly for remachining. There are also many situations where the work piece is in a locality that does not have a machine locally available to perform the machining operations required. The workpiece then must be shipped, often hundreds of miles at great expense, to a machine shop having a machine with the capability to perform the machining operations.
A portable lathe as disclosed in U.S. Pat. No. 4,327,613 issued to Melby may be utilized to machine the spindles on axles without the requirement of disassembly. The lathe, however, is limited in that it will perform machining operations only on an end portion of the spindle or similar member such as a shaft.
There are numerous applications where machining is required on a shaft other than its end portions. Until now there has not been a machine that was mountable on the shaft other than by sliding the lathe over the end of the shaft. This meant that the shaft to be machined had to be removed from it supportive structure so the lathe could be mounted on the shaft. Even at that it could only address an end portion of the shaft. When a shaft was constructed with an eccentric or crank arm or other obstruction, the lathe may not have a large enough center opening to permit the lathe to pass over the device. Thus the lathe would not have the capability of being positioned to the section of the shaft that required machining even when the shaft was removed from the structure.
The present invention fills that need.